1. Field of the Invention
The present invention relates to a new packaging structure, with shock diffusion functions, convenient for transporting or storing a packaged product such as a circuit unit having a printed wiring board.
Various types of communication apparatuses, information processing apparatuses, and measuring apparatuses, use circuit units having printed wiring boards, for instance, which are equipped with signal processing power having a very large capacity and great accuracy, and composed of a high density of electronic components.
Such circuit units are typically transported to a site where the apparatus is to be set up in individual packages separate from each other and the rest of the apparatus. Thus, great care needs to be taken in packaging the units so as to protect them from various vibration and shock impacts during transportation of the units, and during storage in a warehouse. Particularly, the packaged units will need to be protected from unpredictably high shock impacts from dropping due to carelessness during human handling or collapsing of stored piles.
FIG. 26 is a diagrammatic representation of a circuit unit as an example of a product contained within the present invention, wherein FIG. A shows a top view, FIG. B a side view, and FIG. C a front view. In the circuit unit 1 of this figure, electrical components are connected to a circuit pattern, comprising the circuit functions, on the surface of a printed wiring board 2, and a metallic shield cover 3 is mounted over the entire surface of the board 2 so as to protect the circuit unit 1 electromagnetically.
On the front side, a metallic front panel 4 is placed in order to arrange operation components and various indications, and at its ends, rotational lever plug fitting 5 are placed on the printed wiring board 2 so that the panel 4 can be easily put on and taken off from a shelf of the apparatus.
Also, on the back side, multipolar connectors 6, which are plugged into and thus electrically connected to the connector of the backboard of the apparatus shelf, are vertically aligned and connected to the printed wiring board 2.
2. Related Art
The conventional way of packaging a product such as the circuit unit 1 for its transportation, etc. is (see FIG. 27): to cover the circuit unit 1 with a transparent film 11 made of conductive synthetic resin in order to protect the unit from electrostatics, to insert it into a frame 12 made of expanded polystyrene resin or expanded urethane resin; to place sheets 13 of the same material on the top and bottom of the unit within the frame 12 in order hold it in place; to place boards 14 also of the same material on the top and bottom surface of the frame 12; to place cardboards 16 provided with cushion sheets 15 on the top and bottom; and then to put the unit packaged in this order into a cardboard box 17 as shown in FIG. 27A. An illustration of the completed box package is shown in FIG. 27B.